LEIBNIZ: HOW THE SOUL ACTS ON THE BODY

[BH p89] [A VI 4, p1367]

The soul acts on the body in the same way that God acts on the world: that is, not by way of miracle, but by mechanical laws, and so if (though it is impossible) minds were removed and the laws of nature remained, the same would happen as if minds existed, and also as if books were being written and read by human machines which understand nothing. But we must realise that this is impossible, that minds might be removed without violating the laws of mechanics. For the general laws of mechanics are the decrees of the divine will, and the particular laws of mechanics in each body (which follow from the general laws) are the decrees of the soul, or from its form, tending to its own good or perfection. And so God is that mind which leads all things to general perfection. But the soul is that perceiving power, which in each person tends to its particular perfection. But souls arose only when God impressed a tendency [conatus] to particular perfection on all of them, so that from the conflict there might arise the greatest possible perfection. All things in the whole of nature can be explained not only by final causes, but also by efficient causes. Nature does nothing in vain, nature acts by the shortest ways, provided they are according to rule. The shortest ways are to be sought not in actually breaking limits, but in touching them. But this is noted in passing. Souls do not act upon bodies without order, nor does God so act upon nature, even if things may appear to happen without order, because things were so established from the beginning so that the general order involves something extraordinary in appearance.